#include "flash.h"

u16 SPI_FLASH_TYPE=W25Q64;//默认就是25Q64

/*
 * 4Kbytes为一个Sector
 * 16个扇区为1个Block
 *
 * W25X16
 * 容量为2M字节,共有32个Block,512个Sector
 * W25Q128
 * 容量为16M字节,共有128个Block,4096个Sector
 */

//初始化SPI FLASH的IO口
void SPI_Flash_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE );

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;  //SPI CS
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;  //复用推挽输出
    GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    GPIO_SetBits(GPIOA,GPIO_Pin_4);

    SPI1_Init();		   //初始化SPI
    SPI1_SetSpeed(SPI_BaudRatePrescaler_4);	//设置为18M时钟,高速模式
    SPI_FLASH_TYPE=SPI_Flash_ReadID();//读取FLASH ID.
}

//读取SPI_FLASH的状态寄存器
//BIT7  6   5   4   3   2   1   0
//SPR   RV  TB BP2 BP1 BP0 WEL BUSY
//SPR:默认0,状态寄存器保护位,配合WP使用
//TB,BP2,BP1,BP0:FLASH区域写保护设置
//WEL:写使能锁定
//BUSY:忙标记位(1,忙;0,空闲)
//默认:0x00
u8 SPI_Flash_ReadSR(void)
{
    u8 byte=0;
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_ReadStatusReg);    //发送读取状态寄存器命令
    byte=SPI1_ReadWriteByte(0Xff);             //读取一个字节
    SPI_FLASH_CS=1;                            //取消片选
    return byte;
}
//写SPI_FLASH状态寄存器
//只有SPR,TB,BP2,BP1,BP0(bit 7,5,4,3,2)可以写!!!
void SPI_FLASH_Write_SR(u8 sr)
{
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_WriteStatusReg);   //发送写取状态寄存器命令
    SPI1_ReadWriteByte(sr);               //写入一个字节
    SPI_FLASH_CS=1;                            //取消片选
}
//SPI_FLASH写使能
//将WEL置位
void SPI_FLASH_Write_Enable(void)
{
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_WriteEnable);      //发送写使能
    SPI_FLASH_CS=1;                            //取消片选
}
//SPI_FLASH写禁止
//将WEL清零
void SPI_FLASH_Write_Disable(void)
{
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_WriteDisable);     //发送写禁止指令
    SPI_FLASH_CS=1;                            //取消片选
}
//读取芯片ID W25X16的ID:0XEF14
u16 SPI_Flash_ReadID(void)
{
    u16 Temp = 0;
    SPI_FLASH_CS=0;
    SPI1_ReadWriteByte(0x90);//发送读取ID命令
    SPI1_ReadWriteByte(0x00);
    SPI1_ReadWriteByte(0x00);
    SPI1_ReadWriteByte(0x00);
    Temp|=SPI1_ReadWriteByte(0xFF)<<8;
    Temp|=SPI1_ReadWriteByte(0xFF);
    SPI_FLASH_CS=1;
    return Temp;
}
//读取SPI FLASH
//在指定地址开始读取指定长度的数据
//pBuffer:数据存储区
//ReadAddr:开始读取的地址(24bit)
//NumByteToRead:要读取的字节数(最大65535)
void SPI_Flash_Read(u8* pBuffer,u32 ReadAddr,u16 NumByteToRead)
{
    u16 i;
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_ReadData);         //发送读取命令
    SPI1_ReadWriteByte((u8)((ReadAddr)>>16));  //发送24bit地址
    SPI1_ReadWriteByte((u8)((ReadAddr)>>8));
    SPI1_ReadWriteByte((u8)ReadAddr);
    for(i=0; i<NumByteToRead; i++)
    {
        pBuffer[i]=SPI1_ReadWriteByte(0XFF);   //循环读数
    }
    SPI_FLASH_CS=1;                            //取消片选
}
//SPI在一页(0~65535)内写入少于256个字节的数据
//在指定地址开始写入最大256字节的数据
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大256),该数不应该超过该页的剩余字节数!!!
void SPI_Flash_Write_Page(u8* pBuffer,u32 WriteAddr,u16 NumByteToWrite)
{
    u16 i;
    SPI_FLASH_Write_Enable();                  //SET WEL
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_PageProgram);      //发送写页命令
    SPI1_ReadWriteByte((u8)((WriteAddr)>>16)); //发送24bit地址
    SPI1_ReadWriteByte((u8)((WriteAddr)>>8));
    SPI1_ReadWriteByte((u8)WriteAddr);
    for(i=0; i<NumByteToWrite; i++)SPI1_ReadWriteByte(pBuffer[i]); //循环写数
    SPI_FLASH_CS=1;                            //取消片选
    SPI_Flash_Wait_Busy();					   //等待写入结束
}
//无检验写SPI FLASH
//必须确保所写的地址范围内的数据全部为0XFF,否则在非0XFF处写入的数据将失败!
//具有自动换页功能
//在指定地址开始写入指定长度的数据,但是要确保地址不越界!
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大65535)
//CHECK OK
void SPI_Flash_Write_NoCheck(u8* pBuffer,u32 WriteAddr,u16 NumByteToWrite)
{
    u16 pageremain;
    pageremain=256-WriteAddr%256; //单页剩余的字节数
    if(NumByteToWrite<=pageremain)pageremain=NumByteToWrite;//不大于256个字节
    while(1)
    {
        SPI_Flash_Write_Page(pBuffer,WriteAddr,pageremain);
        if(NumByteToWrite==pageremain)break;//写入结束了
        else //NumByteToWrite>pageremain
        {
            pBuffer+=pageremain;
            WriteAddr+=pageremain;

            NumByteToWrite-=pageremain;			  //减去已经写入了的字节数
            if(NumByteToWrite>256)pageremain=256; //一次可以写入256个字节
            else pageremain=NumByteToWrite; 	  //不够256个字节了
        }
    };
}
//写SPI FLASH
//在指定地址开始写入指定长度的数据
//该函数带擦除操作!
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大65535)
u8 SPI_FLASH_BUF[4096];
void SPI_Flash_Write(u8* pBuffer,u32 WriteAddr,u16 NumByteToWrite)
{
    u32 secpos;
    u16 secoff;
    u16 secremain;
    u16 i;
    secpos=WriteAddr/4096;//扇区地址 0~511 for w25x16
    secoff=WriteAddr%4096;//在扇区内的偏移
    secremain=4096-secoff;//扇区剩余空间大小

    if(NumByteToWrite<=secremain)secremain=NumByteToWrite;//不大于4096个字节
    while(1)
    {
        SPI_Flash_Read(SPI_FLASH_BUF,secpos*4096,4096);//读出整个扇区的内容
        for(i=0; i<secremain; i++) //校验数据
        {
            if(SPI_FLASH_BUF[secoff+i]!=0XFF)break;//需要擦除
        }
        if(i<secremain)//需要擦除
        {
            SPI_Flash_Erase_Sector(secpos);//擦除这个扇区
            for(i=0; i<secremain; i++)	 //复制
            {
                SPI_FLASH_BUF[i+secoff]=pBuffer[i];
            }
            SPI_Flash_Write_NoCheck(SPI_FLASH_BUF,secpos*4096,4096);//写入整个扇区

        } else SPI_Flash_Write_NoCheck(pBuffer,WriteAddr,secremain);//写已经擦除了的,直接写入扇区剩余区间.
        if(NumByteToWrite==secremain)break;//写入结束了
        else//写入未结束
        {
            secpos++;//扇区地址增1
            secoff=0;//偏移位置为0

            pBuffer+=secremain;  //指针偏移
            WriteAddr+=secremain;//写地址偏移
            NumByteToWrite-=secremain;				//字节数递减
            if(NumByteToWrite>4096)secremain=4096;	//下一个扇区还是写不完
            else secremain=NumByteToWrite;			//下一个扇区可以写完了
        }
    }
}
//擦除整个芯片
//整片擦除时间:
//W25X16:25s
//W25X32:40s
//W25X64:40s
//等待时间超长...
void SPI_Flash_Erase_Chip(void)
{
    SPI_FLASH_Write_Enable();                  //SET WEL
    SPI_Flash_Wait_Busy();
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_ChipErase);        //发送片擦除命令
    SPI_FLASH_CS=1;                            //取消片选
    SPI_Flash_Wait_Busy();   				   //等待芯片擦除结束
}
//擦除一个扇区
//Dst_Addr:扇区地址 0~511 for w25x16
//擦除一个山区的最少时间:150ms
void SPI_Flash_Erase_Sector(u32 Dst_Addr)
{
    Dst_Addr*=4096;
    SPI_FLASH_Write_Enable();                  //SET WEL
    SPI_Flash_Wait_Busy();
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_SectorErase);      //发送扇区擦除指令
    SPI1_ReadWriteByte((u8)((Dst_Addr)>>16));  //发送24bit地址
    SPI1_ReadWriteByte((u8)((Dst_Addr)>>8));
    SPI1_ReadWriteByte((u8)Dst_Addr);
    SPI_FLASH_CS=1;                            //取消片选
    SPI_Flash_Wait_Busy();   				   //等待擦除完成
}
//等待空闲
void SPI_Flash_Wait_Busy(void)
{
    while ((SPI_Flash_ReadSR()&0x01)==0x01);   // 等待BUSY位清空
}
//进入掉电模式
void SPI_Flash_PowerDown(void)
{
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_PowerDown);        //发送掉电命令
    SPI_FLASH_CS=1;                            //取消片选
//    delay_us(3);                               //等待TPD
}
//唤醒
void SPI_Flash_WAKEUP(void)
{
    SPI_FLASH_CS=0;                            //使能器件
    SPI1_ReadWriteByte(W25X_ReleasePowerDown);   //  send W25X_PowerDown command 0xAB
    SPI_FLASH_CS=1;                            //取消片选
//    delay_us(3);                               //等待TRES1
}


























